Tiffany did 8 more sit-ups than Emily at night. Tiffany did 12 sit-ups. How many sit-ups did Emily do?
Answer: Tiffany did 12 sit-ups, and Emily did 8 fewer than that, so find the difference. The difference is $12 - 8$ sit-ups. She did $12 - 8 = 4$ sit-ups.